1. Field
The following description relates to a driving technology of a power factor correction controlling circuit. The following description also relates to a power factor correction controlling circuit and a corresponding driving method for stably controlling a power factor correction controlling circuit, regardless of a load condition and an input voltage condition.
2. Description of Related Art
In a circuit, a power factor indicates power delivery effectiveness. The power factor is represented as a division of real power being actually delivered by an apparent power, thereby indicating a product of effective values of a voltage and a current. When the voltage and the current correspond to sine waves in form, the power factor may be changed according to a phase difference of the sine waves and may be improved when the phase difference is relatively small between the sine waves. Therefore, generally, a power factor correction may indicate an operation for modifying an input current form into the sine wave form and thereby decreasing the phase difference between the voltage and the current of a power signal.
An alternative power factor correction controlling circuit generates a control signal after delaying an error amplifier output in a start-up operation. Also, such a power factor correction controlling unit forcibly decreases a level of an error amplification signal based on a load condition and an input voltage condition. The level of the error amplification signal may be maintained during a time being set through using a delay circuit. Then, when the start-up operation is completed, the error amplification signal is returned to a normal output voltage.
In such an approach, it takes a long time for the conventional power factor correction controlling circuit to operate in a start-up process because the load condition and the input voltage condition are considered and the delay circuit is used. Also, a circuit configuration of the power factor correction controlling circuit may be restricted in order to speed up a control response time in a start-up time process. When an output voltage reaches a constant level, but it is not to a sufficient level, an error in the power factor correction controlling circuit may occur during the start-up operation because of the output of an error amplifier. Also, the power factor correction controlling circuit may delay a stabilization time because a flat interval occurs in the operation of the delay circuit.